Cover locking means for pressure cookers



Oct 21, 1952 G. c. WYMAN COVER LOCKING MEANS FOR PRESSURE COOKERS FiledMarch 31, 1948 3 Sheets-Sheet 1 v I; 17106213112": Glenn 6. Wyman. 7M

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Oct. 21, 1952 e. c. WYMAN COVER LOCKING MEANS FOR PRESSURE COOKERS FiledMarch 31, 1948 5 Sheets-Sheet 2 v I ITLDEWZ'OT: 9167111 0. Wgrnarw.

Maul, WY

Oct. 21, 1952 a. c. WYMAN 7 COVER LOCKING MEANS FOR PRESSURE COOKERSFiled March 31, 1948 w s a g 35 6 W\ w 3 Q. I m n n e 70 6 Patented Oct.21, 1952 COVER LOCKENG MEANS FOR PRESSURE" COOKEBS Glenn C. Wyman, Rome,N. Y., assignor to Revere Copperand Brass Incorporated, Rome, N. 1 acorporation of Maryland Application March 31, 1948, Serial No. 18,280

My invention relates to pressure cookers. The invention has among itsobjects a pressure cooker having provision-for enforcing-venting thereofbefore the cover can be opened.

3Clairns. (o1. 22o 40 edge of this flange is an'inwardly turneddownwardly' extending frusto-conical flange 23 extending entirely aboutthe cover. Carriedby the cover at its under side is a gasket -ring;25 orThe above and other objects of theinvention greater height thantheflange 23, this ring being will be best understood from the followingdeformed of flexible material such as synthetic rubscription when readin the light of the'accomber, shaped to fit into the space between thepanying drawings of a specific embodiment of the flanges 2| and 23 andto provide a lower portion invention, while the scope of the inventionwill 21 which projects radially beyond theouter side be moreparticularly pointed out in the appended of the flange 23 at its loweredge so as to bear claims. uninterruptedly against the inner .wall ofthe In the drawings: i frusto-conical portion 5 of the container whenFig.1 is a plan of a pressure cooker according the cover is assembledwiththe latter. to the invention; I As shown, the cover is providedwitha radially Fig. 2 shows a detail of Fig. 1, on an enlargedprojecting handle 29 provided with the handle scale, with parts omitted;I grips 3|. This handle is provided with abase Fig. 3 is an elevation ofa pressure cooker acportion 33 which, and the adjacent portion of thecording to Fig. 1, with parts in section; handle conform to the uppersides of the dome- Fig. 4 is a bottom view of the weight gauge aoshapedportion I9 and annular flange 2| of the cording to Figs. 1' and'3; coverto which they are secured preferably by F 5 is a bottom View Of gment Ot e welding. Secured to the under sideof the handle cover handle beforebeing attached to the cover; 29, preferably by Welding, i th b 35 of F ia i n on th lin efi of Fig. 1, on strip-like member which, at its endadjacent. the an enlarged scale; cover, is provided with a downturnedportion 31, 7 s a'fragmehtaiy section 011 the line which latter, at itslower end, is upwardly turned of Fig.6; Y I to form a hook 39. l i s. '8a d -a r sp v y ns c r- When the parts are in the. position shown byresponding o 6 showing the pa fi the drawings the cover is retained on'the conent operative positions; and tainer by the container lip lpositioned above the is a View Of the o k cover flange 2| and by thecontainer lip 9 posibe acco the preceding figures. tioned above thecover hook 39.. When the cover The Pressure Cooker illustrated y t d isinitially placed on the container a clearance 43 in s compr es a co apreferably formed exists between the container lip 7 and cover flange ofsheet metal such as stainless steel, having a 2|, and an equal clearance45 between the conbottom wall I and cylindrical side walls 3. 'Adtainerlip I! and cover hook 39, the projecting jacent their upper edges t eside Wells are formed portion 27 of the gasket ring 25 bearing againstto present an outwardly flared frustc-conical port frusto-conicalcontainer portion 5 o as t tidI 5'e i3 entirely ebouiisaid Wails- At itsseal the joint between the cover and container pp edge s frusto-conieelportion is formed and thus permit pressure to build up in the cooker. topresent an inwardly turned p 1 extending When the pressure builds up thecover rises to abo said portion approximately At 40 take up theclearances 43 and 45, the gasket due theside of t sto-conical portiondiamett its resiliency and the pressure in the cooker Ticaily Oppositethe p I said port o is formed remaining in contact with thefrusto-conical con- With an outwa y projecting downwardly turned tainerportion 5 so that at all times the gasket hp 9 of much s o angulareXileni than the renders the joint between the cover and the conlip 1.Midway its length the lip 9' is shown as 45 tainer steam tight I vformed with, a notch Carried by the i As shown, the base portion 33 ofthe handle tainer is a ,mdiauy projectin? handie havmg and portion ofthe cover immediately below it abase portlpn Secured to fi ifi areformed with a cylindrical perforation M in of fi i preffambly by we Iswhich is received the exteriorly cylindrical body dle being providedw1th the handle grips ll. 5 49 f 1 f d f a nt t i 1 -.As shown, thecover, which also is formed of por Ion 0 1 r r,es1 ma er a sheet metal,preferably stainless steel, is shaped Such as Synthet1c mbber f may besprung to present a dome-likecentral portion |9 sur- Into the-perforatwnandreadlly rounded by a flattened relatively narrow annular i forrepleceinehil-vv Preferably, h b f Y 1 flange 2|. Integral with theouter peripheral Mon 49 of the plug 1s of smaller outside diameter thanthe perforation 41 to permit the plug to slide laterally relative to thecover. As shown,

the plug is retained in the perforation by an upper outwardly projectingannular flange 5| formed as an integral part of the plug and resting onthe upper side of the base portion 33 of the cover handle, and by anoutwardly projecting annular flange 53 formed as an integral part of theplug and cooperating with the bottom surface of an annular recess 55formed about the perforation at the under side of the cover. As shown,the flange 53 at its upper edge is provided with a relatively thinradially projecting annular portion 51. the flange 53, including thecontiguous upper surface of the flange portion 51, is cupped, as

indicated by the surface 59 (Fig. 6), to cause the upper side of theflange portion 51 adjacent its periphery to be in yielding continuouscon'ta'ct throughout its extent with the bottom of the recess 55. Thisinsures that when the cover is initially placed on the container, andthe cooker vent opening 6| in the plug is closed by the valvehereinafter described, pressure may build up in the cooker. Whenpressure builds up the flange 53, 57 of the plug is distorted so thatthe cupped surface 59 substantially throughout its extent and radialwidth. will be firmly seated on the bottom of the recess 55.

As illustrated, the cover handle 29 adjacent the base portion 33 of thehandle at each of opposite sides is provided with an. upstanding ear 63,these ears carrying a pin 65 extending from one ear to the other.Pivoted for swinging movement on this ,pin is an elongated hub 61 whichfits between the ears. This hub is formed as an integral part of thebottom plate 69 of a combined weight valve and pressure gauge having thecasing H, the bottom plate being secured to said casing by screws 1-3.Carried by the bottom plate at its underside is a projectingfrusto-conical. portion "I5 which, when the parts are in the positionshown by-Fig. 6, projects into the bore of a metal bushing 1?, whichbore forms part of the vent opening 54 of the plug carried by the cover,the projection under such conditions seating on the upper inner end edgeof the bushing to close said opening and prevent escape of steam fromthe cooker.

As shown, the projection T5 of the weight valve is provided with athrough opening F'QQleading to a chamber Bl between the bottom plate 69and -a flexible diaphragm 8'3 soldered continuously about its peripheryto the flange 85 ofv the weight valve casing TI. This diaphragm isconnected by a member. 87 to mechanism (not shown) for operatinganindicator hand '89 cooperating with the graduated dial 91 positionedbeneath a crystal 93 .at the upper side of the weight valve casing, sothat when the cover vent opening is closed the hand 89 will indicate thepressure in the cooker.

As further illustrated, the portion of the handle 29 between the ears 63thereof is formed on its upperside with a cylindrical recess 95 (Fig. 6)which loosely receives a cylindrical lug 9'! formed integrally with andprojecting downwardly from the apex portion of a bent or angle lever 99,the convex. portions of this lever at opposite sides of the lug 97swingingly or rockably resting upon the upper surface of the handlemember. At its outer end the lever 9'9 is formed with a head or weightit]! which intermediate its width carries a downwardly projecting pin orlook Hi3 received loosely within a The upper surface of perforation I05formed in the handle 29. It will be observed that when the parts are inthe position shown by Fig. 6, that is to say, when the cooker isv notunder pressure, and in the position of parts shown by Fig. 8 when thecooker is under pressure, the pin I03 is received in the notch II in thelip 9 of the container so as to prevent rotation of the cover relativeto the container for disengaging the former from the latter.

As shown, the hub portion 61 of the bottom plate of the weight valve isformed with a pro- 'jecting portion Hi! the outer convex surface 109 ofwhich presents a cam surface adapted to engage with the upper side ofthe upwardly bent tail portion H l of the lever 99. When the weightvalve is swung .to its position shown by Fig. 9 this cam surface willengage the tail-piece of the lever to swing the lever in such directionas will pull the pin I03 out of the notch ll of the container lip 9, sothat the cover may then be rotated relative to the container for openingthe cooker. It will be observed that, when the parts are in the positionshown by Fig-.9, the upper edge portion 413 of theweight valve easing IIwill rest on the head -llJl of the lever 99-, under which condition, thecenter of gravity of the Weight valve having been moved to the right ofthe pivot pin 65, the parts will remain the position shown by Fig. -9tomaintai-n the cover vent opening 6| in open condition. In theseconnections it will be observed that after the weight valve is securedto the cover removal of the lever 99 is prevented by reason of the ing9'! and pin I03 being received in the-recess and openingl05,respectively, and by the weight valve preventingsuiflcien-tmovementofthe lever away from the cover body tow-ithdraw saidlug and pin from such recess and opening.

In operating the cooker, after the container is charged with food to becooked the covermay be placed on the container and secured thereto inthe manner hereinbefore described, the weight valve for such purposebeing moved to its position shown by Fig. 9 to raise the pin 103 so thatthe cover and container handlesmay be brought into vertical alignment,under wnlch conditions the hook 39 on the cover handle is underthecontainer hp 9 and the pin 103 immediately over the notch l l in thelip 9. Heating'of the contents of the cooker will drive air out of thecontainer through the cooker vent opening ;6l-. Assoc-n as steam isobserved to escape from the vent opening the weight valve-maybe swung onits pivot to close the vent opening so as to cause pressure to build upwithin the cooker. Swinging of the weight valve to close the ventopening causes the lever 99 to fall by gravity, and the pin: 103 toe-nterthe notch H, so that the cooker-cannot be opened until the weightvalve is: again movedto its position shown by Fig. 9.

It will be further observed that the construe tion described insuresthatwhen 'thecooker is under pressure the operator will vent-it byswinging the weight valve 'to its position shown by Fig. 9 before thecover icanbe removed irom the cooker. When the parts are: in theirposition shown by Fig. 8 the cam surface lilil is out of contact withthe lever '99. 'This permits the weightvalve partially to open thecooker vent opening when the pressure builds up to a predeterminedmaximum, so thatsuch maximum pressure will not be exceeded, and the"weight valve to again close the'vent opening if the pressure falls below'sucii maxi-mum after the v'en-topem ing is thus partially opened.

' It will be understood that within the scope of the appended claimswide deviations may be made from the form of the invention describedwithout departing from the spirit of the invention.

I claim:

1. A pressure cooker comprising a container, a cover formed with a ventopening, radially projecting handles carried by said container andcover, respectively, a weight valve swingingly mounted on the upper sideof said cover, which weight valve has a position of swinging in which itcontrols said vent opening and another position' of swinging in which itmaintains said vent opening open, said container and cover carryingcooperating portions operated into engaged position by rotating thecover relative to the container to bring said handles into Verticalalignment for securing said cover to said container in steam-tightrelation, a lever swingingly mounted intermediate its length on theupper side of the cover, one end portion of said lever carrying adownwardly projecting portion operatively adapted to cooperate with thecontainer for preventing movement of said handles out of verticalalignment, the opposite end of said lever having a portion adapted to beengaged by said weight valve when the latter is swung into its saidposition in which it maintains said vent opening open for raising saiddownwardly projecting portion out of cooperation with said container forpermitting said handles to be moved out of vertical alignment.

2. A pressure cooker comprising a, container, a cover for saidcontainer; means for securing the cover to the container operated intoengaged and released positions by rotation of the cover relative to thecontainer; means for establishing and maintaining a predeterminedpressure within the cooker comprising a vent opening formed in thecover, a movable valve cooperating with said opening adapted to be urgedtoward open position by presure within the cooker, a weight forcontrolling said valve swingingly carried by the cover for manualmovement relative thereto from a first position in which the weight isoperative to urge the'valve toward closed position in opposition to theforce exerted on the valve by pressure within the cooker whereby toestablish and maintain such predetermined pressure to a second positionin which the weight is inoperative to so urge the valve, means forlocking the cover against rotation from its position in which it issecured to the container to its position in which it is releasedtherefrom, comprising a part fixedly carried by the container presentingan abutment and a second part movably carried by the cover to thecontainer operated into engaged and released positions by rotation ofthe cover relative to the container; means for establishing andmaintaining a, predetermined pressure with in the cooker comprising avent opening formed in the cover, a movable valve cooperating with saidopening adapted to be urged toward open position by pressure within thecooker, a weight for controlling said valve swingingly carried by thecover for manual movement relative thereto from a first position inwhich the weight is Loperative to urge the valve toward closed posi-'tion in opposition to the force exerted on the valve by pressure withinthe cooker to a second position in which the weight is inoperative toso.

urge the valve means for locking the cover against rotation from itsposition, in which it is secured to the container to its position inwhich it'is released therefrom, comprising a part fixedly carried by thecontainer presentin an abutment, a; member swingingly carried by thecover comprising a' second part movable by swinging of said member intoand out of locking relation -with said abutment, and means operated byswinging of said weight for causing said member to swing to a positionin which said second part is out of such locking relation when saidweight is swung to its said second position and for causing said memberto swing to a position in whichsaid second part is in such lockingrelation when said weight is swung to its said first position.

I GLENN C. WYMAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 191,059 Kagy et a1 May 22, 18772,191,975 Stephens Feb. 27, 1940 2,297,378 Wittenberg Sept. 29, 19422,308,320 Stephens Jan. 12, 1943 2,436,566 Goldberg 1 Feb. 24, 1948FOREIGN PATENTS Number Country Date 12,969 Austria Aug. 0, 1903

